Starting with bindgen 0.73.2 [1], `#[allow(unnecessary_transmutes)]`
are used, even when `--rust-target 1.85` is passed.
However, the lint was introduced in Rust 1.88.0. Thus building with
older Rust versions warns like:
error: unknown lint: `unnecessary_transmutes`
--> rust/uapi/uapi_generated.rs:26294:13
|
26294 | #[allow(unnecessary_transmutes)]
| ^^^^^^^^^^^^^^^^^^^^^^
|
= note: `-D unknown-lints` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(unknown_lints)]`
Thus allow `unknown_lints` in the generated bindings -- only when building
with older Rust versions.
I have asked upstream if this is intentional [1], i.e. if we are supposed
to always allow unknown lints in case `bindgen` uses such attributes,
or whether it is an oversight.
[ Emilio said it wasn't intentional -- we will work around it for now
on the kernel side. - Miguel ]
Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Cc: Emilio Cobos Álvarez <emilio@crisal.io>
Link: https://github.com/rust-lang/rust-bindgen/pull/3455#issuecomment-5588526559 [1]
Assisted-by: LLM
Link: https://patch.msgid.link/20260908170539.345207-1-ojeda@kernel.org
[ Removed the `cfg` for `allow(unnecessary_transmutes)` as suggested by
Gary. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Starting with Rust 1.100.0 (expected 2026-11-12), Clippy warns:
warning: the loop variable `i` is only used to index `self.decimals`
--> drivers/gpu/drm/drm_panic_qr.rs:410:18
|
410 | for i in 0..len {
| ^^^^^^
|
note: for this index operation
--> drivers/gpu/drm/drm_panic_qr.rs:411:13
|
411 | self.decimals[i] = (chunk % 10) as u8;
| ^^^^^^^^^^^^^^^^
= help: for further information visit https://rust-lang.github.io/rust-clippy/main/index.html#needless_range_loop
= note: `-W clippy::needless-range-loop` implied by `-W clippy::all`
= help: to override `-W clippy::all` add `#[allow(clippy::needless_range_loop)]`
help: consider using an iterator
|
410 - for i in 0..len {
410 + for <item> in self.decimals.iter_mut().take(len) {
|
The lint did not trigger here before because it could not handle arrays
behind a field access such as `self.decimals` -- Clippy was improved to
catch those cases [1][2].
Thus clean the warning by iterating over a slice rather than using
`take()` so that an out-of-range `len` still triggers the same bounds
check as the indexed loop.
Cc: stable@vger.kernel.org # Needed in 6.18.y and later.
Link: https://github.com/rust-lang/rust-clippy/issues/16631 [1]
Link: https://github.com/rust-lang/rust-clippy/pull/16634 [2]
Assisted-by: LLM
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patch.msgid.link/20260826145642.43807-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The `rustc-dev` components for Rust 1.82.0 through 1.87.0 include a
precompiled `zerocopy_derive` procedural macro in the sysroot. This
range includes Rust 1.85.0, our minimum supported version.
This makes `rusttest` fail because the compiler finds both the sysroot
copy and the copy built in `rust/test`:
error[E0464]: multiple candidates for `dylib` dependency `zerocopy_derive` found
--> rust/kernel/prelude.rs:70:9
|
70 | pub use zerocopy_derive::{
| ^^^^^^^^^^^^^^^
|
= note: candidate #1: .../lib/rustlib/x86_64-unknown-linux-gnu/lib/libzerocopy_derive-54d2b38896fa6bc5.so
= note: candidate #2: .../rust/test/libzerocopy_derive.so
Commit fe39a233ea ("rust: kbuild: disambiguate `zerocopy` for
`rusttest`") fixed the equivalent ambiguity for `zerocopy`.
Thus point to the dependency explicitly in this case too.
Cc: Antoni Boucher <bouanto@zoho.com>
Cc: stable@vger.kernel.org
Fixes: 5060549804 ("rust: zerocopy-derive: enable support in kbuild")
Link: https://patch.msgid.link/20260823193529.156066-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit
`objtool` errors such as:
vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a:
can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd
The reason is that in such builds, the Clang invocation that compiles
the combined Rust plus helpers bitcode emits LLVM bitcode (again) --
the final code generation happens in the linker's LTO step, which the
`-mllvm` trap options passed to Clang do not reach.
This, in turn, means that unreachable traps are missing, and the
impossible paths do not merely fallthrough to the next symbol, but past
the end of their own section, since LTO builds place each function in
its own section.
Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always
emits machine code directly, with the traps in place.
Assisted-by: LLM
Cc: Gary Guo <gary@garyguo.net>
Cc: Boqun Feng <boqun@kernel.org>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Matthew Maurer <mmaurer@google.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Fixes: 3a2486cc1d ("kbuild: rust: provide an option to inline C helpers into Rust")
Acked-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
When `CONFIG_RUST_INLINE_HELPERS` is enabled, it is possible to hit
`objtool` warnings like:
vmlinux.o: warning: objtool: _R..._4cmdq12CommandToGsp4init()
falls through to next function _R..._4core5array4iter8IntoIterRShKj3_EEEBa_()
`rustc` normally emits traps for unreachable paths. However, under
`CONFIG_RUST_INLINE_HELPERS=y`, `rustc` emits LLVM bitcode and Clang
performs final code generation after the helper bitcode is linked,
but Clang does not trap unreachable IR by default.
In turn, this means `objtool` follows compiler-generated impossible Rust
`enum` paths through alignment padding into the next function, resulting
in fallthrough warnings.
Thus pass the LLVM `trap-unreachable` option to the final Clang invocation
and suppress traps immediately after `noreturn` calls, which `objtool`
already recognizes as dead ends. The combination of both flags makes it
match `rustc`'s behavior.
Rust 1.85.0 (the minimum supported one) supports LLVM >= 18, and both
flags are available in LLVM 18.
Assisted-by: LLM
Cc: Gary Guo <gary@garyguo.net>
Cc: Boqun Feng <boqun@kernel.org>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Matthew Maurer <mmaurer@google.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Fixes: 3a2486cc1d ("kbuild: rust: provide an option to inline C helpers into Rust")
Acked-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260816133233.197500-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
When the pointer formatting series [1] is applied and KUnit tests
are enabled, `objtool` would report an error with any of our
supported Rust versions. For instance, with Rust 1.97.1:
rust/kernel.o: error: objtool: _R..._4core3fmt7Pointer3fmtB7_()
falls through to next function _R..._4core7convert5AsRefNtB5_4BStrE6as_ref()
Or, with Rust 1.85.0:
rust/kernel.o: error: objtool: _R..._4core3fmt7Pointer3fmtB7_()
falls through to next function _R..._4core3ffi5c_str4CStrENtNtBS_3fmt7Display3fmtB7_()
This happens due to calls to the `noreturn` symbol:
core::str::slice_error_fail
Thus add the mangled one to the list so that `objtool` knows it is
actually `noreturn`.
See commit 56d680dd23 ("objtool/rust: list `noreturn` Rust functions")
for more details.
[ While the series [1] mentioned above was not applied in a way
that triggered this, Gary found another case [2]:
I am seeing this function causing issue on my 1.85.1 -Os build, although the
error message is different this time:
rust/kernel.o: warning: objtool: _R..._5range9RangeFromjEE5indexCsldbe0TGTmNx_6kernel+0x1d:
stack state mismatch: cfa1=4+8 cfa2=4+16
Disassembly shows that the function call before the warning location
is a call to _4core3str16slice_error_fail, and objtool thought it can
return (which will end up with a unbalanced stack if it does return).
Thus apply it. - Miguel ]
Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Reported-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/rust-for-linux/anLxXvCKBcAVf91_@google.com/
Link: https://lore.kernel.org/rust-for-linux/20260706-hashedptr-v13-0-377a07f2f78d@kylinos.cn/ [1]
Link: https://lore.kernel.org/rust-for-linux/DKS7U9UHY6XR.2JC0EBIPCI06Z@garyguo.net/ [2]
Link: https://patch.msgid.link/20260805144524.233362-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Pull pin-init updates from Gary Guo:
"User-visible changes:
- Merge the '__pinned_init' and '__init' methods and make 'Init'
a marker trait.
- Introduce public APIs 'raw_init' and 'raw_try_init' to prevent users
from needing to invoke the internal '__pinned_init'/'__init' methods.
- Emit errors for duplicate '#[pin]' attributes.
- Link 'Zeroable::zeroed' and 'pin_init::zeroed' in documentation.
Other changes:
- Fix unwind safety issues.
- Clean up lint 'allow' and 'expect's.
- Overhaul '#[cfg]' handling to pave the way for tuple structs and
self-referential structs.
- Mark many functions as '#[inline]' for better codegen with '-C
opt-level=s' ('CC_OPTIMIZE_FOR_SIZE')."
* tag 'pin-init-v7.3' of https://github.com/Rust-for-Linux/linux:
rust: pin-init: add `#[inline]` to small functions
rust: pin-init: remove `__pinned_init` method for `cfg(kernel)`
rust: treewide: replace `__pinned_init` with `raw_[try_]init`
rust: pin-init: add `raw_init` and `raw_try_init` and recommend over `__init`
rust: pin-init: merge `__pinned_init` and `__init`
rust: pin-init: examples: use `Wrapper::pin_init` instead of manual reimplementation
rust: pin-init: mark `pin_init::zeroed` and `Zeroable::zeroed` as `#[inline]`
rust: pin-init: docs: link `Zeroable::zeroed` and `pin_init::zeroed` in documentation
rust: pin-init: internal: rework how `#[pin_data]` handles cfg
rust: pin-init: make `[pin_]chain` unwind safe
rust: pin-init: make `[pin_]init_array_from_fn` unwind safe
rust: pin-init: internal: generate brace in macro for init code blocks
rust: pin-init: internal: remove `allow` and `expect`s that don't fire
rust: pin-init: remove redundant clippy expects in doc tests
rust: pin-init: examples: fix incorrect drop
rust: pin-init: internal: error on duplicate `#[pin]` attribute
`command -v` behaves differently on `dash` vs. `bash` when faced with
a file without the execute bit.
Thus, for the non-executable `rustc` and `bindgen` tests, support both
possible outputs that the script currently gives.
This makes the test script clean on distributions like Fedora.
Reviewed-by: Onur Özkan <work@onurozkan.dev>
Link: https://patch.msgid.link/20260719130723.162899-1-ojeda@kernel.org
[ Added custom assertion message as suggested. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Starting with Rust 1.99.0 (expected 2026-10-01), `objtool` may report:
rust/kernel.o: warning: objtool: _R..._6kernel3str9parse_intaNtNtB2_7private12FromStrRadix14from_str_radix()
falls through to next function _R..._6kernel3str9parse_intaNtNtB2_7private12FromStrRadix16from_u64_negated()
due to calls to the `noreturn` symbol:
core::num::from_ascii_bytes_radix_panic
The function was renamed from `from_ascii_radix_panic` [1], which is
already in the list.
Thus add the new one to the list so that `objtool` knows it is actually
`noreturn`.
See commit 56d680dd23 ("objtool/rust: list `noreturn` Rust functions")
for more details.
Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://github.com/rust-lang/rust/pull/159554 [1]
Tested-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260728191448.349241-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The `Firmware` example crafts an `ARef<Device>` using a null pointer,
which breaks the safety requirements of `Device::get_device()`.
Instead, pass an `ARef` via a parameter, which is simpler, avoids UB
and removes an `unsafe` block.
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260711180231.229525-1-ojeda@kernel.org
[ Also drop the second superfluous empty line. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Starting with Rust 1.98.0 (expected 2026-08-20), Rust is introducing a
couple new lints, `invalid_runtime_symbol_definitions` (deny-by-default)
and `suspicious_runtime_symbol_definitions` (warn-by-default), which check
the signature of items whose symbol name is a runtime symbol expected by
`core`.
Our build hits the second one, i.e. the warning:
error: suspicious definition of the runtime `strlen` symbol used by the standard library
--> rust/bindings/bindings_generated.rs:20018:5
|
20018 | pub fn strlen(s: *const ffi::c_char) -> usize;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: expected `unsafe extern "C" fn(*const i8) -> usize`
found `unsafe extern "C" fn(*const u8) -> usize`
= help: either fix the signature or remove any attributes like `#[unsafe(no_mangle)]`, `#[unsafe(export_name = "strlen")]`, or `#[link_name = "strlen"]`
= help: allow this lint if the signature is compatible
= note: `-D suspicious-runtime-symbol-definitions` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(suspicious_runtime_symbol_definitions)]`
error: suspicious definition of the runtime `strlen` symbol used by the standard library
--> rust/uapi/uapi_generated.rs:14236:5
|
14236 | pub fn strlen(s: *const ffi::c_char) -> usize;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: expected `unsafe extern "C" fn(*const i8) -> usize`
found `unsafe extern "C" fn(*const u8) -> usize`
= help: either fix the signature or remove any attributes like `#[unsafe(no_mangle)]`, `#[unsafe(export_name = "strlen")]`, or `#[link_name = "strlen"]`
= help: allow this lint if the signature is compatible
= note: `-D suspicious-runtime-symbol-definitions` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(suspicious_runtime_symbol_definitions)]`
Thus `allow` the lint in `bindings` and `uapi`.
A more targeted alternative to avoid `allow`ing it would be to pass
`--blocklist-function strlen` to `bindgen`, but we would perhaps need
to adjust if other C headers end up adding more (or Rust checking more).
Since it is just the less critical one that we hit, and since eventually
this should be properly fixed by getting upstream Rust to provide a flag
like GCC/Clang's `-funsigned-char` [2][3], just `allow` it for now.
Cc: Urgau <urgau@numericable.fr>
Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Link: https://github.com/rust-lang/rust/pull/155521 [1]
Link: https://github.com/rust-lang/rust/issues/138446 [2]
Link: https://github.com/Rust-for-Linux/linux/issues/355 [3]
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Link: https://patch.msgid.link/20260615143225.471756-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Onur has been involved with the Rust for Linux project for a year now. He
works on the Tyr driver for Arm Mali GPUs [1] and has been driving the
`ww_mutex` series and the SRCU abstractions, as well as improving the
core Rust support in several areas.
In addition, he is already a reviewer of the `RUST [SYNC]` entry and has
been involved with upstream Rust -- for instance, he led the bootstrap
team for two years.
His expertise with the language and its toolchain will be very useful to
have around in the future. Thus add him to the `RUST` entry as reviewer.
Link: https://rust-for-linux.com/tyr-gpu-driver [1]
Acked-by: Onur Özkan <work@onurozkan.dev>
Acked-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260611055538.61425-4-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Alexandre has been involved with the Rust for Linux project for more
than a year now. He is one of the main contributors to Nova [1], the
Rust driver for NVIDIA GPUs, and has authored core Rust infrastructure
motivated by that work, such as the `num` module with the `Bounded`
integer type, the `register!` and `bitfield!` macros, as well as
improvements to abstractions like DMA.
He maintains the nova-core driver, as well as the `RUST [NUM]`, `RUST
[BITFIELD]` and `RUST [INTEROP]` entries. In addition, he has been very
active reviewing Rust code in the mailing list.
He also proposed and implemented the `int_lowest_highest_one` feature
in the Rust standard library [2], which we should eventually use in
the kernel.
His experience maintaining a major Rust GPU driver and the abstractions
it needs will be very useful to have around in the future. Thus add him
to the `RUST` entry as reviewer.
Link: https://rust-for-linux.com/nova-gpu-driver [1]
Link: https://github.com/rust-lang/rust/issues/145203 [2]
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260611055538.61425-3-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Tamir has been involved with the Rust for Linux project for more than
a year and a half now. He has been working on improving the integration
between the kernel and the Rust language and tooling: he led the effort
to replace the kernel's own `CStr` type with the standard library's,
and reworked the rust-analyzer integration, among other things.
He is already the maintainer of the `RUST [RUST-ANALYZER]` and `XARRAY API
[RUST]` entries. In addition, he has been active reviewing Rust code in
the mailing list.
He is also a long-time contributor to the upstream Rust project, including
on topics that matter for the Linux kernel [1].
His expertise with the language and its tooling will be very useful to
have around in the future. Thus add him to the `RUST` entry as reviewer.
Link: https://github.com/rust-lang/rust/pull/139994 [1]
Acked-by: Tamir Duberstein <tamird@kernel.org>
Acked-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260611055538.61425-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Daniel has been involved with the Rust for Linux project for more than
three years now. He is the lead of the Tyr driver for Arm Mali GPUs
[1] and submitted many of the core abstractions that drivers need: the
`irq` module, system resources, `IoMem`, the regulator API, the `bits`
module, the basic USB abstractions... He is also working on the initial
Rust V4L2 support [2].
He is already a maintainer and reviewer of several Rust-related entries,
and he has been very active reviewing Rust code in the mailing list.
His experience building Rust drivers and the APIs they require will be
very useful to have around in the future. Thus add him to the `RUST`
entry as reviewer.
Link: https://rust-for-linux.com/tyr-gpu-driver [1]
Link: https://lore.kernel.org/rust-for-linux/20250818-v4l2-v1-0-6887e772aac2@collabora.com/ [2]
Acked-by: Daniel Almeida <daniel.almeida@collabora.com>
Acked-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260611055538.61425-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Starting with Rust 1.98.0 (expected 2026-08-20), the compiler has changed
how the resolution algorithm works [1] in upstream commit c4d84db5f184
("Resolver: Batched import resolution."), and it now spots:
error: unused import: `flags::*`
--> rust/kernel/str.rs:7:9
|
7 | flags::*,
| ^^^^^^^^
|
= note: `-D unused-imports` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(unused_imports)]`
It happens to not be needed because the `prelude::*` already provides
the flags.
Thus clean it up.
Cc: stable@vger.kernel.org # Needed in 6.18.y and later (prelude added to `str`).
Link: https://github.com/rust-lang/rust/pull/145108 [1]
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260609104152.261145-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Introduce support for `zerocopy` [1][2]:
Fast, safe, compile error. Pick two.
Zerocopy makes zero-cost memory manipulation effortless. We write
`unsafe` so you don't have to.
It essentially provides derivable traits (e.g. `FromBytes`) and macros
(e.g. `transmute!`) for safely converting between byte sequences and
other types. Having such support allows us to remove some `unsafe` code.
It is among the most downloaded Rust crates (top #50 recent, top #100
all-time downloads; according to crates.io), and it is also used by the
Rust compiler itself.
The series starts with a few preparation commits, then the `zerocopy`
and `zerocopy-derive` crates are added. Finally, an example patch using
it is on top, removing one `unsafe impl`.
I had to adapt the crates slightly (just +2/-3 lines), but both patches
could potentially be provided upstream eventually. Please see the
commits for details.
In total, it is about ~39k lines added, ~32k without counting `benches/`
which are just for documentation purposes.
See the cover letter for `syn` for some more details about depending on
third-party crates in commit 54e3eae855 ("Merge patch series "`syn`
support"").
The codegen of an isolated example function similar to the patch on top
is essentially identical. It also turns out that (for that particular
case) `zerocopy`'s version, even under `debug-assertions` enabled, has
no remaining panics, unlike a few in the current code (because the
compiler can prove the remaining `ub_checks` statically).
So their "fast, safe" does indeed check out -- at least in that case.
P.S. This version of `zerocopy` has already the unstable `Ptr{,Inner}`
types -- to play with them, please use:
make ... KRUSTFLAGS=--cfg=zerocopy_unstable_ptr
Link: https://github.com/google/zerocopy [1]
Link: https://docs.rs/zerocopy [2]
Link: https://patch.msgid.link/20260608141439.182634-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Linux is built with `-Dnon_ascii_idents`. However, `zerocopy-derive`
uses a non-ASCII character (`ẕ`) internally, which in turn triggers
the lint when attempting to use derives like `FromBytes`:
error: identifier contains non-ASCII characters
--> rust/kernel/lib.rs:153:9
|
153 | a: u32,
| ^
|
= note: requested on the command line with `-D non-ascii-idents`
This was already noticed by another project using
`#![deny(non_ascii_idents)]` [1]. `zerocopy` added an
`#[allow(non_ascii_idents)]` [2], but it does not work since, at the
moment, the `non_ascii_idents` lint is a `crate_level_only` one, and thus
`allow`s only work at the crate root level.
Due to this, an issue about relaxing this restriction was created in
upstream Rust [3] some months ago.
Thus work around it here by using another prefix. The likelihood of a
collision is very small for us, since we control the callers, and this
will hopefully be fixed soon at either the `zerocopy` or the Rust level.
I filed an issue [4] about it with upstream `zerocopy` as requested
and we discussed this with upstream Rust and `zerocopy`: the Rust issue
got nominated and a PR [5] to relax the restriction was submitted by
Joshua. Upstream `zerocopy` prefers that approach, so if Rust merges it,
then it means we will be able to remove the workaround when we bump the
MSRV, thus likely late 2027, since we follow Debian Stable.
Cc: Joshua Liebow-Feeser <joshlf@google.com>
Cc: Jack Wrenn <jswrenn@google.com>
Link: https://github.com/google/zerocopy/issues/2880 [1]
Link: https://github.com/google/zerocopy/pull/2882 [2]
Link: https://github.com/rust-lang/rust/issues/151025 [3]
Link: https://github.com/google/zerocopy/issues/3427 [4]
Link: https://github.com/rust-lang/rust/pull/157497 [5]
Link: https://patch.msgid.link/20260608141439.182634-16-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Originally, when the Rust upstream `alloc` standard library crate was
vendored, the SPDX License Identifiers were added to every file so that
the license on those was clear. The same happened with the vendoring of
`proc_macro2`, `quote` and `syn`. Please see:
commit 057b8d2571 ("rust: adapt `alloc` crate to the kernel")
commit 69942c0a89 ("rust: syn: add SPDX License Identifiers")
commit ddfa1b279d ("rust: quote: add SPDX License Identifiers")
commit a9acfceb96 ("rust: proc-macro2: add SPDX License Identifiers")
Thus do the same for the `zerocopy-derive` crate.
This makes `scripts/spdxcheck.py` pass: use parentheses like commit
06e9bfc1e5 ("ionic: make spdxcheck.py happy") did since we have two
`OR` operators in the expression (three licenses).
Finally, as requested, I filed an issue [1] with upstream about it.
Cc: Joshua Liebow-Feeser <joshlf@google.com>
Cc: Jack Wrenn <jswrenn@google.com>
Link: https://github.com/google/zerocopy/issues/3428 [1]
Link: https://patch.msgid.link/20260608141439.182634-15-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
With all the new files in place and ready from the new crate, enable
the support for it in the build system.
In addition, skip formatting for this vendored crate.
Finally, there are no generated symbols expected from `zerocopy`, thus
skip adding the `exports` generation.
Link: https://patch.msgid.link/20260608141439.182634-13-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The kernel builds `core` with the `no_fp_fmt_parse` `--cfg`, which means
we do not have support for formatting floating point primitives. However,
`zerocopy` expects those implementations to exist:
error[E0277]: `f32` doesn't implement `core::fmt::Display`
--> rust/zerocopy/src/byteorder.rs:172:29
|
172 | $trait::fmt(&self.get(), f)
| ----------- ^^^^^^^^^^^ the trait `core::fmt::Display` is not implemented for `f32`
| |
| required by a bound introduced by this call
...
907 | / define_type!(
908 | | An,
909 | | "A 32-bit floating point number",
910 | | F32,
... |
922 | | []
923 | | );
| |_- in this macro invocation
|
= help: the following other types implement trait `core::fmt::Display`:
i128
i16
i32
i64
i8
isize
u128
u16
and 4 others
= note: this error originates in the macro `impl_fmt_trait` which comes from the expansion of the macro `define_type` (in Nightly builds, run with -Z macro-backtrace for more info)
Thus work around it by skipping those implementations in `zerocopy`.
Ideally, `zerocopy` would have the equivalent of `no_fp_fmt_parse`;
and, indeed, upstream just added it [1] after I filed an issue [2]
about it as requested. We can try it in a future update of our
vendored copy.
Cc: Joshua Liebow-Feeser <joshlf@google.com>
Cc: Jack Wrenn <jswrenn@google.com>
Link: https://github.com/google/zerocopy/pull/3429 [1]
Link: https://github.com/google/zerocopy/issues/3426 [2]
Link: https://patch.msgid.link/20260608141439.182634-11-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Originally, when the Rust upstream `alloc` standard library crate was
vendored, the SPDX License Identifiers were added to every file so that
the license on those was clear. The same happened with the vendoring of
`proc_macro2`, `quote` and `syn`. Please see:
commit 057b8d2571 ("rust: adapt `alloc` crate to the kernel")
commit 69942c0a89 ("rust: syn: add SPDX License Identifiers")
commit ddfa1b279d ("rust: quote: add SPDX License Identifiers")
commit a9acfceb96 ("rust: proc-macro2: add SPDX License Identifiers")
Thus do the same for the `zerocopy` crate.
This makes `scripts/spdxcheck.py` pass: use parentheses like commit
06e9bfc1e5 ("ionic: make spdxcheck.py happy") did since we have two
`OR` operators in the expression (three licenses).
SPDX identifiers are not added to the `benches` files because they are
included in rendered documentation. Nevertheless, the `README.md` to be
added by a later commit mentions the license.
Finally, as requested, I filed an issue [1] with upstream about it.
Cc: Joshua Liebow-Feeser <joshlf@google.com>
Cc: Jack Wrenn <jswrenn@google.com>
Link: https://github.com/google/zerocopy/issues/3428 [1]
Link: https://patch.msgid.link/20260608141439.182634-10-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Since we are adding one more proc macro crate (`zerocopy-derive`),
we are refactoring their handling.
Thus, instead of using `libmacros_extension` as the common variable to
hold the extension for all of them, use a dedicated variable with a more
generic name (including for its implementation).
Link: https://patch.msgid.link/20260608141439.182634-6-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Since we are adding one more proc macro crate (`zerocopy-derive`),
we are refactoring their handling.
`libpin_init_internal_extension` was added to mimic the setup for
`macros`, but it is not used, since the extension is expected to be
the same.
Thus remove it.
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/20260608141439.182634-4-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
A future commit adding `zerocopy` support will need to pass an environment
variable during its build.
Thus add support for an `--envs` parameter, similar to `--cfgs`, that
allows to pass a map of variables to set for a given crate.
This allows us to keep a single source of truth for those values.
No change intended in the generated `rust-project.json`.
Acked-by: Tamir Duberstein <tamird@kernel.org>
Link: https://patch.msgid.link/20260608141439.182634-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Pull pin-init updates from Gary Guo:
"User visible changes:
- Do not generate 'non_snake_case' warnings for identifiers that are
syntactically just users of a field name. This would allow all
'#[allow(non_snake_case)]' in nova-core to be removed, which I will
send to the nova tree next cycle.
- Filter non-cfg attributes out properly in derived structs. This
improves pin-init compatibility with other derive macros.
- Insert projection types' where clause properly.
Other changes:
- Bump MSRV to 1.82, plus associated cleanups.
- Overhaul how init slots are projected. The new approach is easier
to justify with safety comments.
- Mark more functions as inline, which should help mitigate the
super-long symbol name issue due to lack of inlining.
- Various small code quality cleanups."
* tag 'pin-init-v7.2' of https://github.com/Rust-for-Linux/linux: (27 commits)
rust: pin_init: internal: use `loop {}` to produce never value
rust: pin-init: remove `E` from `InitClosure`
rust: pin-init: move `InitClosure` out from `__internal`
rust: pin-init: docs: fix typos in MaybeZeroable documentation
rust: pin-init: internal: suppress `non_snake_case` lint in `[pin_]init!`
rust: pin-init: internal: suppress `non_snake_case` lint in `#[pin_data]`
rust: pin-init: internal: pin_data: filter non-`#[cfg]` attr in generated code
rust: pin-init: internal: project using full slot
rust: pin-init: internal: project slots instead of references
rust: pin-init: internal: make `make_closure` inherent methods
rust: pin-init: internal: use marker on drop guard type for pinned fields
rust: pin-init: internal: init: handle code blocks early
rust: pin-init: internal: add `PhantomInvariant` and `PhantomInvariantLifetime`
rust: pin-init: internal: pin_data: add struct to record field info
rust: pin-init: internal: pin_data: use closure for `handle_field`
rust: pin-init: examples: fix `useless_borrows_in_formatting` clippy warning
rust: pin-init: internal: remove `collect_tuple` polyfill after MSRV bump
rust: pin-init: internal: turn `PhantomPinned` error into warnings
rust: pin-init: cleanup workaround for old Rust compiler
rust: pin-init: fix badge URL in README
...
Starting with Rust 1.98.0 (expected 2026-08-20), the target spec will not
support `x86-softfloat` anymore [1]. Instead, `softfloat` should be used,
which is an alias. Otherwise, one gets:
error: error loading target specification: rustc-abi: invalid rustc abi: 'x86-softfloat'. allowed values: 'x86-sse2', 'softfloat' at line 3 column 32
|
= help: run `rustc --print target-list` for a list of built-in targets
Thus conditionally use one or the other depending on the version.
The alias has existed since Rust 1.95.0 (released 2026-04-16) [2], but
use the newer version instead to avoid changing how the build works for
existing compilers, at least until more testing takes place.
Cc: Ralf Jung <post@ralfj.de>
Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Link: https://github.com/rust-lang/rust/pull/157151 [1]
Link: https://github.com/rust-lang/rust/pull/151154 [2]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260530114925.260754-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Pull alloc updates from Danilo Krummrich:
- Fix the 'Vec::reserve()' doctest to properly account for the existing
vector length in the capacity assertion.
- Fix an incorrect operator in the 'Vec::extend_with()' SAFETY comment;
add a doc test demonstrating basic usage and the zero-length case.
- Cleanup all imports in the alloc module and its doctests to use the
"kernel vertical" import style.
* tag 'alloc-7.2-rc1' of https://github.com/Rust-for-Linux/linux:
rust: alloc: cleanup doctest imports to "kernel vertical" style
rust: alloc: cleanup imports and use "kernel vertical" style
rust: alloc: fix `Vec::extend_with` SAFETY comment
rust: alloc: add doc test for `Vec::extend_with`
rust: alloc: fix assert in `Vec::reserve` doc test
Pull pin-init updates from Benno Lossin:
- Replace the 'Zeroable' impls for 'Option<NonZero*>' with impls of
'ZeroableOption' for 'NonZero*'.
- Improve feature gate handling for unstable features.
- Declutter the documentation of implementations of 'Zeroable' for
tuples.
- Replace uses of 'addr_of[_mut]!' with '&raw [mut]'.
* tag 'pin-init-v7.1' of https://github.com/Rust-for-Linux/linux:
rust: pin-init: replace `addr_of_mut!` with `&raw mut`
rust: pin-init: implement ZeroableOption for NonZero* integer types
rust: pin-init: doc: de-clutter documentation with fake-variadics
rust: pin-init: properly document let binding workaround
rust: pin-init: build: simplify use of nightly features
Pull timekeeping updates from Andreas Hindborg:
- Expand the example section in the 'HrTimer' documentation.
- Mark the 'ClockSource' trait as unsafe to ensure valid values for
'ktime_get()'.
- Add 'Delta::from_nanos()'.
This is a back merge since the pull request has a newer base -- we will
avoid that in the future.
And, given it is a back merge, it happens to resolve the "subtle" conflict
around '--remap-path-{prefix,scope}' that I discussed in linux-next [1],
plus a few other common conflicts. The result matches what we did for
next-20260407.
The actual diffstat (i.e. using a temporary merge of upstream first) is:
rust/kernel/time.rs | 32 ++++-
rust/kernel/time/hrtimer.rs | 336 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 362 insertions(+), 6 deletions(-)
Link: https://lore.kernel.org/linux-next/CANiq72kdxB=W3_CV1U44oOK3SssztPo2wLDZt6LP94TEO+Kj4g@mail.gmail.com/ [1]
* tag 'rust-timekeeping-for-v7.1' of https://github.com/Rust-for-Linux/linux:
hrtimer: add usage examples to documentation
rust: time: make ClockSource unsafe trait
rust/time: Add Delta::from_nanos()
As proposed in the past in e.g. LPC 2025 and the Maintainers Summit [1],
we are going to follow Debian Stable's Rust versions as our minimum
supported version.
Debian Trixie was released with a Rust 1.85.0 toolchain [2], which it
still uses to this day [3] (i.e. no update to Rust 1.85.1).
Debian Trixie was released with `bindgen` 0.71.1, which it also still
uses to this day [4].
Debian Trixie's release happened on 2025-08-09 [5], which means that a
fair amount of time has passed since its release for kernel developers
to upgrade.
Thus bump the minimum to the new versions, i.e.
- Rust: 1.78.0 -> 1.85.0
- bindgen: 0.65.1 -> 0.71.1
There are a few main parts to the series, in this order:
- A few cleanups that can be performed before the bumps.
- The Rust bump (and its cleanups).
- The `bindgen` bump (and its cleanups).
- Documentation updates.
- The `cfi_encoding` patch, added here, which needs the bump.
- The per-version flags support and a Clippy cleanup on top.
Link: https://lwn.net/Articles/1050174/ [1]
Link: https://www.debian.org/releases/trixie/release-notes/whats-new.en.html#desktops-and-well-known-packages [2]
Link: https://packages.debian.org/trixie/rustc [3]
Link: https://packages.debian.org/trixie/bindgen [4]
Link: https://www.debian.org/releases/trixie/ [5]
Link: https://patch.msgid.link/20260405235309.418950-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The Clippy `precedence` lint was extended in Rust 1.85.0 to include
bitmasking and shift operations [1]. However, because it generated
many hits, in Rust 1.86.0 it was split into a new `precedence_bits`
lint which is not enabled by default [2].
In other words, only Rust 1.85 has a different behavior. For instance,
it reports:
warning: operator precedence can trip the unwary
--> drivers/gpu/nova-core/fb/hal/ga100.rs:16:5
|
16 | / u64::from(regs::NV_PFB_NISO_FLUSH_SYSMEM_ADDR::read(bar).adr_39_08()) << FLUSH_SYSMEM_ADDR_SHIFT
17 | | | u64::from(regs::NV_PFB_NISO_FLUSH_SYSMEM_ADDR_HI::read(bar).adr_63_40())
18 | | << FLUSH_SYSMEM_ADDR_SHIFT_HI
| |_________________________________________^
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#precedence
= note: `-W clippy::precedence` implied by `-W clippy::all`
= help: to override `-W clippy::all` add `#[allow(clippy::precedence)]`
help: consider parenthesizing your expression
|
16 ~ (u64::from(regs::NV_PFB_NISO_FLUSH_SYSMEM_ADDR::read(bar).adr_39_08()) << FLUSH_SYSMEM_ADDR_SHIFT) | (u64::from(regs::NV_PFB_NISO_FLUSH_SYSMEM_ADDR_HI::read(bar).adr_63_40())
17 + << FLUSH_SYSMEM_ADDR_SHIFT_HI)
|
While so far we try our best to keep all versions Clippy-clean, the
minimum (which is now Rust 1.85.0 after the bump) and the latest stable
are the most important ones; and this may be considered a "false positive"
with respect to the behavior in other versions.
Thus allow this lint for this version using the per-version flags
mechanism introduced in the previous commit.
Link: https://github.com/rust-lang/rust-clippy/issues/14097 [1]
Link: https://github.com/rust-lang/rust-clippy/pull/14115 [2]
Link: https://lore.kernel.org/rust-for-linux/DFVDKMMA7KPC.2DN0951H3H55Y@kernel.org/
Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260405235309.418950-34-ojeda@kernel.org
[ Added paragraph from commit message to comment. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Currently the example in the documentation shows a version-based name
for the Kconfig example:
RUSTC_VERSION_MIN_107900
The reason behind it was to possibly avoid repetition in case several
features used the same minimum.
However, we ended up preferring to give them a descriptive name for each
feature added even if that could lead to some repetition. In practice,
the repetition has not happened so far, and even if it does at some point,
it is not a big deal.
Thus replace the example in the documentation with one of our current
examples (after removing previous ones from the bump), to show how they
actually look like, and in case someone `grep`s for it.
In addition, it has the advantage that it shows the `RUSTC_HAS_*`
pattern we follow in `init/Kconfig`, similar to the C side.
Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260405235309.418950-31-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
With the Rust version bump in place, the `RUSTC_HAS_COERCE_POINTEE`
Kconfig (automatic) option is always true.
Thus remove the option and simplify the code.
In particular, this includes removing our use of the predecessor unstable
features we used with Rust < 1.84.0 (`coerce_unsized`, `dispatch_from_dyn`
and `unsize`).
Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260405235309.418950-11-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
With the Rust version bump in place, the `RUSTC_HAS_SLICE_AS_FLATTENED`
Kconfig (automatic) option is always true.
Thus remove the option and simplify the code.
In particular, this includes removing the `slice` module which contained
the temporary slice helpers, i.e. the `AsFlattened` extension trait and
its `impl`s.
Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260405235309.418950-10-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
With the Rust version bump in place, several Kconfig conditions based on
`RUSTC_VERSION` are always true.
Thus simplify them.
The minimum supported major LLVM version by our new Rust minimum version
is now LLVM 18, instead of LLVM 16. However, there are no possible
cleanups for `RUSTC_LLVM_VERSION`.
Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260405235309.418950-9-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
`clippy::incompatible_msrv` is not buying us much, and we discussed
allowing it several times in the past.
For instance, there was recently another patch sent to `allow` it where
needed [1]. While that particular case would not be needed after the
minimum version bump to 1.85.0, it is simpler to just allow it to prevent
future instances.
[ In addition, the lint fired without taking into account the features
that have been enabled in a crate [2]. While this was improved in Rust
1.90.0 [3], it would still fire in a case like this patch. ]
Thus do so, and remove the last instance of locally allowing it we have
in the tree (except the one in the vendored `proc_macro2` crate).
Note that we still keep the `msrv` config option in `clippy.toml` since
that affects other lints as well.
Link: https://lore.kernel.org/rust-for-linux/20260404212831.78971-4-jhubbard@nvidia.com/ [1]
Link: https://github.com/rust-lang/rust-clippy/issues/14425 [2]
Link: https://github.com/rust-lang/rust-clippy/pull/14433 [3]
Link: https://patch.msgid.link/20260405235309.418950-8-ojeda@kernel.org
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
These were likely copied from the `bindings` and `uapi` crates, but are
unneeded since there are no `cfg(test)`s in the bindings.
In addition, the issue that triggered the addition in those crates
originally is also fixed in `bindgen` (please see the previous commit).
Thus remove them.
Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://patch.msgid.link/20260405235309.418950-5-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Clippy in Rust 1.88.0 (only) reports [1]:
warning: variables can be used directly in the `format!` string
--> rust/macros/module.rs:112:23
|
112 | let content = format!("{param}:{content}", param = param, content = content);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args
= note: `-W clippy::uninlined-format-args` implied by `-W clippy::all`
= help: to override `-W clippy::all` add `#[allow(clippy::uninlined_format_args)]`
help: change this to
|
112 - let content = format!("{param}:{content}", param = param, content = content);
112 + let content = format!("{param}:{content}");
warning: variables can be used directly in the `format!` string
--> rust/macros/module.rs:198:14
|
198 | t => panic!("Unsupported parameter type {}", t),
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args
= note: `-W clippy::uninlined-format-args` implied by `-W clippy::all`
= help: to override `-W clippy::all` add `#[allow(clippy::uninlined_format_args)]`
help: change this to
|
198 - t => panic!("Unsupported parameter type {}", t),
198 + t => panic!("Unsupported parameter type {t}"),
|
The reason it only triggers in that version is that the lint was moved
from `pedantic` to `style` in Rust 1.88.0 and then back to `pedantic`
in Rust 1.89.0 [2][3].
In the first case, the suggestion is fair and a pure simplification, thus
we will clean it up separately.
To keep the behavior the same across all versions, and since the lint
does not work for all macros (e.g. custom ones like `pr_info!`), disable
it globally.
Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Link: https://lore.kernel.org/rust-for-linux/CANiq72=drAtf3y_DZ-2o4jb6Az9J3Yj4QYwWnbRui4sm4AJD3Q@mail.gmail.com/ [1]
Link: https://github.com/rust-lang/rust-clippy/pull/15287 [2]
Link: https://github.com/rust-lang/rust-clippy/issues/15151 [3]
Link: https://patch.msgid.link/20260331205849.498295-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Under an UML build for an upcoming series [1], I got `-Wstatic-in-inline`
for `dma_free_attrs`:
BINDGEN rust/bindings/bindings_generated.rs - due to target missing
In file included from rust/helpers/helpers.c:59:
rust/helpers/dma.c:17:2: warning: static function 'dma_free_attrs' is used in an inline function with external linkage [-Wstatic-in-inline]
17 | dma_free_attrs(dev, size, cpu_addr, dma_handle, attrs);
| ^
rust/helpers/dma.c:12:1: note: use 'static' to give inline function 'rust_helper_dma_free_attrs' internal linkage
12 | __rust_helper void rust_helper_dma_free_attrs(struct device *dev, size_t size,
| ^
| static
The issue is that `dma_free_attrs` was not marked `inline` when it was
introduced alongside the rest of the stubs.
Thus mark it.
Fixes: ed6ccf10f2 ("dma-mapping: properly stub out the DMA API for !CONFIG_HAS_DMA")
Closes: https://lore.kernel.org/rust-for-linux/20260322194616.89847-1-ojeda@kernel.org/ [1]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20260325015548.70912-1-ojeda@kernel.org
Starting with the upcoming Rust 1.96.0 (to be released 2026-05-28),
`rustc` introduces the new lint `unused_features` [1], which warns [2]:
warning: feature `used_with_arg` is declared but not used
--> <crate attribute>:1:93
|
1 | #![feature(asm_const,asm_goto,arbitrary_self_types,lint_reasons,offset_of_nested,raw_ref_op,used_with_arg)]
| ^^^^^^^^^^^^^
|
= note: `#[warn(unused_features)]` (part of `#[warn(unused)]`) on by default
The original goal of using `-Zcrate-attr` automatically was that there
is a consistent set of features enabled and managed globally for all
Rust kernel code (modulo exceptions like the `rust/` crated).
While we could require crates to enable features manually (even if we
still keep the `-Zallow-features=` list, i.e. removing the `-Zcrate-attr`
list), it is not really worth making all developers worry about it just
for a new lint.
The features are expected to eventually become stable anyway (most already
did), and thus having to remove features in every file that may use them
is not worth it either.
Thus just allow the new lint globally.
The lint actually existed for a long time, which is why `rustc` does
not complain about an unknown lint in the stable versions we support,
but it was "disabled" years ago [3], and now it was made to work again.
For extra context, the new implementation of the lint has already been
improved to avoid linting about features that became stable thanks to
Benno's report and the ensuing discussion [4] [5], but while that helps,
it is still the case that we may have features enabled that are not used
for one reason or another in a particular crate.
Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Link: https://github.com/rust-lang/rust/pull/152164 [1]
Link: https://github.com/Rust-for-Linux/pin-init/pull/114 [2]
Link: https://github.com/rust-lang/rust/issues/44232 [3]
Link: https://github.com/rust-lang/rust/issues/153523 [4]
Link: https://github.com/rust-lang/rust/pull/153610 [5]
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260312111014.74198-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Custom target specifications are unstable, but starting with Rust 1.95.0,
`rustc` requires to explicitly pass `-Zunstable-options` to use them [1]:
error: error loading target specification: custom targets are unstable and require `-Zunstable-options`
|
= help: run `rustc --print target-list` for a list of built-in targets
David (Rust compiler team lead), writes:
"We're destabilising custom targets to allow us to move forward with
build-std without accidentally exposing functionality that we'd like
to revisit prior to committing to. I'll start a thread on Zulip to
discuss with the RfL team how we can come up with an alternative
for them."
Thus pass it.
Cc: David Wood <david@davidtw.co>
Cc: Wesley Wiser <wwiser@gmail.com>
Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Link: https://github.com/rust-lang/rust/pull/151534 [1]
Reviewed-by: Gary Guo <gary@garyguo.net>
Tested-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260206204535.39431-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Tomonori writes:
"This adds the Rust equivalent of the C's DO_ONCE_LITE and pr_*_once
macros.
A proposal for this feature was made in the past [1], but it didn't
reach consensus on the implementation and wasn't merged.
Unlike the previous proposal, this implements the C's DO_ONCE_LITE
mechanism using a single atomic variable. While it would be possible
to implement the feature entirely as a Rust macro, the functionality
that can be implemented as regular functions has been extracted and
implemented as the OnceLite struct for better code readability.
To make it clear that this feature is intended solely for
print-related functionality (just like in C), the implementation is
placed in print.rs. If an equivalent of std::sync::Once is needed in
the future, it should be based on SetOnce rather than OnceLite. Unlike
std::sync::Once and SetOnce, OnceLite only manages two states:
incomplete and complete.
The do_once_lite macro places the OnceLite object in the .data..once
section, which may be zeroed by memset at any time. While this means
tear reads might happen, OnceLite only manages two states (zero and
non-zero), so no actual problem occurs in practice.
OnceLite currently uses Atomic<i32>, but may be changed to use
Atomic<i8> [2] when it becomes available."
Link: https://lore.kernel.org/rust-for-linux/20241126-pr_once_macros-v4-0-410b8ca9643e@tuta.io/ [1]
Link: https://lore.kernel.org/rust-for-linux/20251115050305.3872412-1-fujita.tomonori@gmail.com/ [2]
Link: https://patch.msgid.link/20251117002452.4068692-1-fujita.tomonori@gmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Gary writes:
"This series converts Rust proc macros that we have to use `syn`,
and replace the custom `quote!` macro that we have with the vendored
`quote!` macro. The `pin-init` macros are not converted yet; Benno
has a work in progress in converting them. They're however converted
to use `quote` and `proc-macro2` crate so our custom `quote!` macro
can be removed.
Overall this improves the robustness of the macros as we have precise
parsing of the AST rather than relying on heuristics to extract needed
information from there. This is also a quality-of-life improvement
to those using language servers (e.g. Rust analyzer) as the span
information of the proc macros are now preserved which allows the
"jump-to-definition" feature to work, even when used on completely
custom macros such as `module!`.
Miguel gave a very good explanation on why `syn` is a good idea in the
patch series that introduced it [1], which I shall not repeat here."
The `pin-init` rewrite was merged just before this one.
Link: https://lore.kernel.org/rust-for-linux/20251124151837.2184382-1-ojeda@kernel.org/ [1]
Link: https://patch.msgid.link/20260112170919.1888584-1-gary@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Pull pin-init updates from Benno Lossin:
"Added:
- Implement 'InPlaceWrite' for '&'static mut MaybeUninit<T>'. This
enables users to use external allocation mechanisms such as
'static_cell'.
- Add Gary Guo as a Maintainer.
Changed:
- Rewrote all proc-macros ('[pin_]init!', '#[pin_data]',
'#[pinned_drop]', 'derive([Maybe]Zeroable)'), using 'syn' with
better diagnostics.
- Support tuple structs in 'derive([Maybe]Zeroable)'.
- Support attributes on fields in '[pin_]init!' (such as
'#[cfg(...)]').
- Add a '#[default_error(<type>)]' attribute to '[pin_]init!' to
override the default error (when no '? Error' is specified).
- Support packed structs in '[pin_]init!' with
'#[disable_initialized_field_access]'.
Removed:
- Remove 'try_[pin_]init!' in favor of merging their feature
with '[pin_]init!'. Update the kernel's own 'try_[pin_]init!'
macros to use the 'default_error' attribute.
Fixed:
- Correct 'T: Sized' bounds to 'T: ?Sized' in the generated
'PinnedDrop' check by '#[pin_data]'."
* tag 'pin-init-v7.0' of https://github.com/Rust-for-Linux/linux:
rust: pin-init: Implement `InPlaceWrite<T>` for `&'static mut MaybeUninit<T>`
MAINTAINERS: add Gary Guo to pin-init
rust: pin-init: internal: init: simplify Zeroable safety check
rust: pin-init: internal: init: add escape hatch for referencing initialized fields
rust: pin-init: internal: init: add support for attributes on initializer fields
rust: init: use `#[default_error(err)]` for the initializer macros
rust: pin-init: add `#[default_error(<type>)]` attribute to initializer macros
rust: pin-init: rewrite the initializer macros using `syn`
rust: pin-init: add `?Sized` bounds to traits in `#[pin_data]` macro
rust: pin-init: rewrite `#[pin_data]` using `syn`
rust: pin-init: rewrite the `#[pinned_drop]` attribute macro using `syn`
rust: pin-init: rewrite `derive(Zeroable)` and `derive(MaybeZeroable)` using `syn`
rust: pin-init: internal: add utility API for syn error handling
rust: pin-init: add `syn` dependency and remove `proc-macro[2]` and `quote` workarounds
rust: pin-init: allow the crate to refer to itself as `pin-init` in doc tests
rust: pin-init: remove `try_` versions of the initializer macros
Pull XArray update from Andreas Hindborg:
- Add '__rust_helper' to XArray abstraction C helpers.
* tag 'rust-xarray-for-v6.20-v7.0' of https://github.com/Rust-for-Linux/linux:
rust: xarray: add __rust_helper to helpers
Miguel Ojeda